#include<stdio.h>
int main(){
    int m,n,i;
    scanf("%d %d",&m,&n);
    double n_fact=1,m_fact=1,npm_fact=1;
    for(i=1;i<=n;i++)n_fact*=(double)i;
    for(i=1;i<=m;i++)m_fact*=(double)i;
    for(i=1;i<=(n-m);i++)npm_fact*=i;
    double result = n_fact/m_fact/npm_fact;
    // printf("%lf,%lf,%lf",n_fact,m_fact,npm_fact);
    printf("result = %.lf\n",result);
    return 0;
}